System and method for controlling wind turbine blades

Abstract

A wind turbine system is presented. The wind turbine system includes a blade comprising an airfoil and a sensing device disposed on a surface of the airfoil, wherein the sensing device generates signals that are representative of pressure deflection on the surface of the airfoil. The wind turbine system further comprises a processing subsystem that receives location details of the sensing device and a transfer function corresponding to the airfoil, determines a location of a stagnation point on the surface of the airfoil based upon the signals and the location details, and determine an angle of attack (AOA) on the surface of the airfoil based upon the location of the stagnation point and the transfer function.

1. A wind turbine system, comprising:
 a blade comprising an airfoil; 
 a sensing device disposed on a surface of the airfoil, wherein the sensing device generates signals that are representative of pressure deflection on the surface of the airfoil; 
 a processing subsystem comprising computer executable instructions configured to execute the steps of:
 receiving location details of the sensing device and a transfer function corresponding to the airfoil; 
 determining a location of a stagnation point with respect to a reference point on the surface of the airfoil based upon the signals and the location details; and 
 determining an angle of attack (AOA) on the surface of the airfoil based upon the location of the stagnation point and the transfer function, wherein the transfer function defines a relationship between the angle of attack and the location of the stagnation point with respect to the reference point. 
 
 
     
     
       2. The wind turbine of  claim 1 , wherein the sensing device comprises a capacitance based membrane pressure strip, a resistance based membrane pressure strip, a resistance sensor, a capacitance sensor, and combinations thereof. 
     
     
       3. The wind turbine of  claim 1 , wherein the sensing device comprises a thickness of less than 6 millimeters. 
     
     
       4. The wind turbine of  claim 1 , wherein a first predefined length of the sensing device is disposed on a pressure side and a second predefined length of the sensing device is disposed on a suction side, and the sensing device extends from a leading edge towards a trailing edge. 
     
     
       5. The wind turbine of  claim 4 , wherein the first predefined length is 80% of the sensing device and the second predefined length is 20% of the sensing device. 
     
     
       6. The wind turbine of  claim 1 , wherein the sensing device is disposed on the pressure side and extends from the leading edge along a third predefined length of a chord of the airfoil. 
     
     
       7. The wind turbine of  claim 6 , wherein the third predefined length is 30% of the length of the chord. 
     
     
       8. The wind turbine of  claim 1 , wherein the airfoil further comprises a sleeve to preserve an aerodynamic performance of the airfoil. 
     
     
       9. The wind turbine of  claim 8 , wherein the sleeve extends from an end to another end of the sensing device such that a location of the sensing device does not overlap with a location of the sleeve. 
     
     
       10. The wind turbine of  claim 8 , wherein a thickness of the sleeve is similar to a thickness of the sensing device. 
     
     
       11. The wind turbine of  claim 1 , wherein one or both ends of the sensing device are tapered. 
     
     
       12. The wind turbine of  claim 1 , wherein the processing subsystem further comprises computer executable instructions to execute the step of optimizing aerodynamics of the blade based upon the AOA. 
     
     
       13. The wind turbine of  claim 1 , wherein the processing subsystem further comprises computer executable instructions to execute the step of determining an optimized angle of attack (AOA) at the surface of the airfoil based upon the determined AOA. 
     
     
       14. The wind turbine of  claim 1 , further comprising a data repository that stores the location details, the transfer function, the location of stagnation point, intermediate results, one or more coefficients of the transfer function, and combinations thereof. 
     
     
       15. A wind turbine system, comprising:
 a plurality of blades, wherein each of the plurality of blades comprises a plurality of airfoils; 
 a sensing device disposed on each of the plurality of airfoils, wherein the sensing device generates signals that are representative of pressure deflection on a corresponding surface of each of the plurality of airfoils; 
 a processing subsystem comprising computer executable instructions configured to execute the steps of:
 receiving location details of the sensing device and a transfer function corresponding to each of the plurality of airfoils; 
 determining a location of a stagnation point, with respect to a reference point, on the corresponding surface of each of the plurality of airfoils based upon the signals and the location details; and 
 determining an angle of attack (AOA) on the corresponding surface of each of the plurality of airfoils based upon the stagnation point and the transfer function, wherein the transfer function defines a relationship between the angle of attack and the location of the stagnation point with respect to the reference point. 
 
 
     
     
       16. A method for determining an angle of attack (AOA) on a surface of an airfoil of a blade, comprising:
 generating signals that are representative of pressure deflection on the surface of the airfoil; 
 receiving location details of the sensing device and a transfer function corresponding to the airfoil; 
 determining a location of a stagnation point, with respect to a reference point, on the surface of the airfoil based upon the signals and the location details; 
 determining an angle of attack (AOA) on the surface of the airfoil based upon the location of the stagnation point and the transfer function, wherein the transfer function defines a relationship between the angle of attack and the location of the stagnation point with respect to the reference point; and 
 adjusting a pitch angle of the blade based on the AOA.